With the fast development of the Internet, it is common to provide telephone service for users via the Internet. There are two popular ways in the prior art to provide IP phone service for users. As shown in FIG. 1, in this first mode, the user of the telephone 1 sends a request for dialing an IP phone call to the user of the phone 7 to an Internet Telephone Provider (ITP) 3 via the PSTN 2, for example, by dialing a special service number such as 17930 to connect with the ITP 3. Then, the user of the telephone 1 inputs the number of the telephone 7 according to the prompt of the ITP 3. The ITP 3 then establishes an Internet link 4 between itself and the gateway router 5 of the PSTN 6 accessed by the phone 7. The users of the telephone 1 and the telephone 7 can now talk with each other through the path as shown in FIG. 1.
However, in this mode, the Internet connection is established between the ITP 3 and the gateway router 5, and the connection between the phone 1 and the ITP 3 is still though PSTN 2. In addition, operations such as data format conversions are executed at the ITP 3 and the gateway router 5. Therefore, the cost of IP phone service is rather high.
The other popular mode is shown in FIG. 2. The difference between this mode and that shown in FIG. 1 is that the Internet connection 3 is established between the computer 2 at the telephone 1 and the ITP 4. The telephone 1 directly dials an IP phone call to the telephone 8 though the Internet connection. The cost in this latter mode is low. However, the computer 2 is necessary at the telephone end as an access device to the Internet. Therefore, the hardware cost is high in this mode.